ArgumentError (Invalid argument(s): argument value for 'return_value' is null)

[mugikhan]

I am getting an error in the latest version of Flutter (3.22.2) and sqlite3 (2.4.2). When checking for all exceptions, it seems to throw this exception ArgumentError (Invalid argument(s): argument value for 'return_value' is null) when closing the database connection. It also seems to occur on any query in the sqlite3_step function. The exception is not thrown in Flutter 3.19.6.

Any idea why the exception might be thrown despite the operations succeeding?

  int sqlite3_step(
    ffi.Pointer<sqlite3_stmt> pStmt,
  ) {
    return _sqlite3_step(
      pStmt,
    );
  }

  int sqlite3_close_v2(
    ffi.Pointer<sqlite3> db,
  ) {
    return _sqlite3_close_v2(
      db,
    );
  }

Flutter info

[✓] Flutter (Channel stable, 3.22.2, on macOS 14.5 23F79 darwin-arm64, locale en-ZA)

[simolus3]

This might be a regression in dart:ffi - thanks for the report. Do you have a stack trace or more details on how I could reproduce this. Do I need to somehow call sqlite3_step after closing? Do you have a complete stack trace on how this call happened?

[JCKodel]

Same here, using the PowerSync plugin (not using Drift):

The stacktrace is:

sqlite3.g.dart, line 59:

  int sqlite3_close_v2(
    ffi.Pointer<sqlite3> db,
  ) {
    return _sqlite3_close_v2(
      db,
    );
  }

FfiBindings, line 133:

  @override
  int sqlite3_close_v2() {
    return bindings.bindings.sqlite3_close_v2(db);
  }

FinalizableDatabase, line 39:

  @override
  void dispose() {
    for (final stmt in _statements) {
      stmt.dispose();
    }

    final code = database.sqlite3_close_v2();
    SqliteException? exception;
    if (code != SqlError.SQLITE_OK) {
      exception = createExceptionRaw(bindings, database, code,
          operation: 'closing database');
    }

    database.deallocateAdditionalMemory();

    if (exception != null) {
      throw exception;
    }
  }
}

DatabaseImplementation, line 232:

  @override
  void dispose() {
    if (_isClosed) return;

    disposeFinalizer.detach(this);
    _isClosed = true;

    for (final listener in _updateListeners) {
      listener.close();
    }
    database.sqlite3_update_hook(null);

    finalizable.dispose();
  }

_PowerSyncDatabaseIsolateArgs, line 546:

  rPort.listen((message) async {
    if (message is List) {
      String action = message[0];
      if (action == 'update') {
        updateController.add('update');
      } else if (action == 'close') {
        // This prevents any further transactions being opened, which would
        // eventually terminate the sync loop.
        await mutex.close();
        db?.dispose();
        db = null;
        updateController.close();
        upstreamDbClient.close();
        Isolate.current.kill();
      }
    }
  });

Basically, PowerSync calls db.dispose() when the sync isolate is done with its job.

I do not know if this is true for SQLite3, but SqliteF has some bugs on database close (because, apparently, Android always have a single connection to SQLite, and if you close it, all other instances using that database also closes, leading to executing queries on a closed database, because, for Android, db is a static singleton >.<)

[simolus3]

This appears to be a VM bug => dart-lang/sdk#56064.

There is a workaround I could apply, but I'll wait to see if this will get fixed and backported.

[simolus3]

I've fixed this in version 2.4.4 of package:sqlite3. It's a workaround though, so if there's a cherry-pick/Dart stable that fixes this problem I'll revert it.